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Verified CAS / Academic Author38 Decoded Studies

Prof. HAO Shu-wei

University of Science and Technology of China

Co-Affiliations:State Key Laboratory of Infrared Science and Technology, Shanghai Institute of Technical Physics, Chinese Academy of SciencesKey Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, China

Research Publications & English Decoded Briefs

Showing 38 publications
Opto-Electronic Advances (光电进展)2026DOI: 10.29026/oea.2026.250263

AI-assisted metaphotonics: A Comprehensive Review of Artificial Intelligence-Driven Approaches for Metaphotonic Systems

The convergence of artificial intelligence (AI) and metaphotonics is creating a new paradigm for controlling light-matter interactions. The synergy of AI's ability to learn complex relationships in multidimensional data and provide ultra-fast inference with the capacity of metaphotonics to engineer optical properties not found in nature is unlocking a new era in computational design, real-time control, and fully automated optical systems. This review provides a comprehensive overview of state-of-the-art AI-driven approaches for metaphotonic systems. We focus on the solutions to real-world problems in accelerating metaphotonic simulations and inverse design, optical data characterization, and the development of fully integrated end-to-end AI-assisted metaphotonic systems. Finally, we provide our perspectives on the future research directions and emerging opportunities at the rapidly evolving intersection of metaphotonics and AI.

Opto-Electronic Advances (光电进展)2026DOI: 10.29026/oea.2026.250177

Soft Chiral Superstructure Enabled Dynamic Polychromatic Holography

Planar optics offers a compact and versatile platform for manipulating multiple dimensions of light parameters and thus has attracted tremendous interest in high-density data storage, high-security information encryption, and holographic displays. It is still challenging to achieve active functionalities via dynamically operating light-matter interactions inside these planar optics. Here, a polymer-stabilized cholesteric liquid crystal (CLC) is adopted as a tunable one-dimensional chiral superstructure. The bandgap tends to change from a periodic helix to a gradient-pitch configuration under direct current (DC) voltage, and the reflection bandwidth varies from a narrow band of 40 nm to a broad band of 180 nm. Off-axis phase-only holograms of three primary colors are properly k-space engineered via a modified Gerchberg-Saxton algorithm, and recorded into the initial alignments of the CLC by photopatterning. By altering the applied DC voltage, the generated holography actively switches between a monochromatic and polychromatic image. Moreover, spin-selective Bragg-Berry phase encoding in photopatterned superstructures with opposite helicity allows distinct holograms (e.g., "weather sign" and "chameleon") to be independently generated and modulated. This work takes full advantage of soft chiral superstructures for on-demand light control and has great potential in dynamic holography, information encryption, and data storage.

Transactions of Nonferrous Metals Society of China (中国有色金属学报)2026DOI: 10.1016/S1003-6326(26)67070-7

CFD modeling of gas−liquid mixing and splashing in industrial-scale bottom-blowing furnace: Effects of melt viscosity

The co-processing of lead-containing waste materials in oxygen bottom-blowing lead smelting alters melt viscosity, which in turn governs gas−liquid mixing efficiency, splashing behavior, and furnace lining erosion. A multi-fluid volume of fluid (VOF) model, incorporating experimentally determined high-lead slag viscosity values, was applied to an industrial-scale bottom-blowing furnace to resolve these coupled phenomena. The simulations demonstrate that optimal gas−liquid mixing occurs at viscosity values of 0.01 and 0.5 Pa·s, whereas minimal splashing is confined to the viscosity range of 0.1−0.25 Pa·s, corresponding to temperatures of approximately 1076−1100 °C. The regions surrounding the oxygen lances are identified as the most susceptible to erosion. Shear stress increases with melt viscosity, rising particularly rapidly within the 0.1−0.25 Pa·s interval. To minimize erosion, the melt viscosity should be maintained within 0.01−0.1 Pa·s. These findings provide quantitative thresholds for viscosity control in industrial bottom-blowing furnaces processing lead-containing secondary materials, enabling trade-offs between mixing intensity, splashing suppression, and lining protection to be optimized on an operational basis.

Int. Journal of Mining Science and Technology (采矿与安全工程)2026DOI: 10.1016/j.ijmst.2026.01.003

Influence of Aggregate Particle Size on Fracture Behavior and Energy Evolution of Cemented Rockfill in the Post-Peak Stage

Cemented rockfill (CRF) combines structural support with sustainable reuse of coal-derived solid waste. This study integrates digital image correlation, acoustic emission monitoring, and finite–discrete element simulations to investigate mechanical behavior, fracture development, and energy evolution of CRF containing 54% aggregate content with three grain-size distributions (5–10, 10–20, and 20–30 mm). Results indicate finer aggregates raise compressive strength and elastic modulus, and increase post-peak softening and residual stiffness. Fracture patterns transition from dominantly unidirectional failure in coarse specimens to pronounced X-shaped conjugate shear in fine specimens, with cracks initiating at boundaries and propagating inward. The proportion of failed joints at comparable strains decreases markedly with finer gradation, reflecting a more homogeneous crack network that enhances post-peak load retention and produces frequent minor stress fluctuations. Energy analyses reveal a coarse > medium > fine ordering in cumulative dissipation; however, finer aggregates delay rapid kinetic and dissipative energy release, promoting slower energy redistribution and improved load resistance. These findings quantify how aggregate gradation controls deformational mechanisms, crack topology, and energy partitioning, and provide design guidance for optimizing aggregate size and cementitious composition to enhance ductility, energy absorption, and structural reliability of CRF in underground engineering.

Journal of Infrared and Millimeter Waves (红外与毫米波学报)2026DOI: 10.11972/j.issn.1001-9014.2026.03.2026043

Mid-Wavelength Infrared Detector Array Based on Black Phosphorus Ink Thin Film

Mid-wavelength infrared (MWIR) imaging technology plays a crucial role in aerospace, medical diagnostics, and autonomous driving. Van der Waals material black phosphorus (BP) exhibits exceptionally high carrier mobility and an ideal direct bandgap, making it a proven candidate for high-performance room-temperature MWIR sensing. However, the stringent growth conditions and anisotropic growth characteristics restrict the development of BP optoelectronic devices to small-scale laboratory demonstrations. Therefore, there is an urgent need to develop large-scale, uniform, and high-performance BP photodetector arrays. This study employed a room temperature preparation technique to deposit a large-area, uniform, low-oxidation BP ink film onto thin-film transistors, resulting in the development of a 64 × 64 high-performance MWIR snapshot photodetector array. The room temperature ink preparation process effectively prevents the oxidation of BP during fabrication, achieving an oxidation loss as low as 1.12%. In addition, a gradient centrifugation strategy was employed to optimize the lateral size and thickness distribution of the nanosheets in the BP ink, thereby facilitating the transport of charge carriers. The BP ink film array demonstrated a high photoresponsivity of 4.52 mA/W in the MWIR range, with pixel light response non-uniformity as low as 10.1%. This study presents a new approach for advancing large-scale MWIR imaging technology.

Int. Journal of Mining Science and Technology (采矿与安全工程)2026DOI: 10.1016/j.ijmst.2026.02.004

Heating Rate Effect of Thermal Expansion in Granite and Implications for Rock Breaking

The influence of the heating rate on the thermo-mechanical response and damage evolution of rock is a critical factor limiting the safety and efficiency of engineering applications. Conventional models are limited, however, as they assume a static coefficient of thermal expansion (CTE) and ignore its dynamic nature under rapid thermal loading. This study confronts this knowledge gap using a synergistic experimental–numerical approach. A custom system combining induction heating and Digital Image Correlation was employed to measure the rate-dependent CTE of both bulk granite and its constituent minerals over various heating rates. These dynamic coefficients were then integrated into a high-fidelity numerical model to simulate microwave-assisted rock breaking. Results definitively show the CTE is strongly rate-dependent. While the quartz phase transition at ~573 °C triggers critical damage, faster heating significantly amplifies strain localization and damage accumulation. Crucially, simulations revealed that under identical microwave loading, the model using dynamic CTE (530 °C/min) reached a 1000 mm² failure area 11 times faster than the model using quasi-static CTE (5 °C/min). This study fundamentally establishes rock's CTE as a dynamic, rate-dependent property, providing a key scientific basis for advancing such thermal fracturing technologies.

China Foundry2026DOI: 10.1007/s41230-026-5206-2

Effect of critical tempering on microstructure evolution, mechanical performance, and corrosion behavior of a cast multiphase stainless steel

A novel cast stainless steel featuring a multiphase microstructure and a nominal composition of Fe-13.5Cr-2.6Si-6.9Ni-1.1Cu-1.1Mn-1.0Mo-0.35Al-0.025C (wt.%) was investigated. Following solution treatment at 1,050 °C and water quenching, the specimens were subjected to further tempering at 570 °C, 610 °C, and 650 °C to explore the effects of critical tempering on microstructure, mechanical properties, and corrosion resistance. Various characterization techniques were employed to examine the phase distribution within the microstructure, with particular attention given to the content and morphology of reverted austenite. Tensile and corrosion tests were carried out to evaluate the performance of the specimens. The results reveal that critical tempering significantly enhances the mechanical properties, with the specimen tempered at 610 °C achieving the highest product of strength and elongation (PSE=23.6 GPa·%), whereas corrosion resistance deteriorates with increasing tempering temperature. Calculations of the martensite start temperature (Ms) and stacking fault energy (γSFE) for the reversed austenite in different specimens indicate that the stability of reversed austenite strongly influences mechanical behavior through the TRIP and TWIP effects. However, tempering-induced Cr segregation at ferrite/martensite interfaces and the formation of Cr-depleted zones become more pronounced at higher tempering temperatures, leading to a degradation in corrosion resistance. Furthermore, multiphase coordinated deformation improves the strength-ductility balance, while corrosion tends to initiate at chemically inhomogeneous phase boundaries.

Nano-Micro Letters2026DOI: 10.1007/s40820-025-01851-9

Moisture-Resistant Scalable Ambient-Air Crystallization of Perovskite Films via Self-Buffered Molecular Migration Strategy

Ambient-air, moisture-assisted annealing is widely used in fabricating perovskite solar cells (PSCs). However, the inherent sensitivity of perovskite intermediate-phase to moisture—due to fast and spontaneous intermolecular exchange reaction—requires strict control of ambient humidity and immediate thermal annealing treatment, raising manufacturing costs and causing fast nucleation of perovskite films. We report herein a self-buffered molecular migration strategy to slow down the intermolecular exchange reaction by introducing a n–butylammonium bromide shielding layer, which limits moisture diffusion into intermediate-phase film. This further endows the notably wide nucleation time and humidity windows for perovskite crystallization in ambient air. Consequently, the optimized 1.68 eV-bandgap n-i-p structured PSC reaches a record-high reverse-scan (RS) PCE of 22.09%. Furthermore, the versatility and applicability of as-proposed self-buffered molecular migration strategy are certified by employing various shielding materials and 1.53 eV-/1.77 eV-bandgap perovskite materials. The n-i-p structured PSCs based on 1.53 eV- and 1.77 eV-bandgap perovskite films achieve outstanding RS PCEs of 25.23% and 19.09%, respectively, both of which are beyond of the state-of-the-art ambient-air processed PSCs.

Nano-Micro Letters2026DOI: 10.1007/s40820-025-01949-0

Crystallographic Engineering Enables Fast Low-Temperature Ion Transport of TiNb2O7 for Cold-Region Lithium-Ion Batteries

TiNb2O7 represents an up-and-coming anode material for fast-charging lithium-ion batteries, but its practicalities are severely impeded by slow transfer rates of ionic and electronic especially at the low-temperature conditions. Herein, we introduce crystallographic engineering to enhance structure stability and promote Li+ diffusion kinetics of TiNb2O7 (TNO). The density functional theory computation reveals that Ti4+ is replaced by Sb5+ and Nb5+ in crystal lattices, which can reduce the Li+ diffusion impediment and improve electronic conductivity. Synchrotron radiation X-ray 3D nano-computed tomography and in situ X-ray diffraction measurement confirm the introduction of Sb/Nb alleviates volume expansion during lithiation and delithiation processes, contributing to enhancing structure stability. Extended X-ray absorption fine structure spectra results verify that crystallographic engineering also increases short Nb-O bond length in TNO-Sb/Nb. Accordingly, the TNO-Sb/Nb anode delivers an outstanding capacity retention rate of 89.8% at 10 C after 700 cycles and excellent rate performance (140.4 mAh g−1 at 20 C). Even at −30 °C, TNO-Sb/Nb anode delivers a capacity of 102.6 mAh g−1 with little capacity degeneration for 500 cycles. This work provides guidance for the design of fast-charging batteries at low-temperature condition.

Nano-Micro Letters2025DOI: 10.1007/s40820-025-01837-7

Scalable and Sustainable Chitosan/Carbon Nanotubes Composite Protective Layer for Dendrite-Free and Long-Cycling Aqueous Zinc-Metal Batteries

Rechargeable aqueous zinc (Zn)-metal batteries hold great promise for next-generation energy storage systems. However, their practical application is hindered by several challenges, including dendrite formation, corrosion, and the competing hydrogen evolution reaction. To address these issues, we designed and fabricated a composite protective layer for Zn anodes by integrating carbon nanotubes (CNTs) with chitosan through a simple and scalable scraping process. The CNTs ensure uniform electric field distribution due to their high electrical conductivity, while protonated chitosan regulates ion transport and suppresses dendrite formation at the anode interface. The chitosan/CNTs composite layer also facilitates smooth Zn2+ deposition, enhancing the stability and reversibility of the Zn anode. As a result, the chitosan/CNTs @ Zn anode demonstrates exceptional cycling stability, achieving over 3000 h of plating/stripping with minimal degradation. When paired with a V2O5 cathode, the composite-protected anode significantly improves the cycle stability and energy density of the full cell. Techno-economic analysis confirms that batteries incorporating the chitosan/CNTs protective layer outperform those with bare Zn anodes in terms of energy density and overall performance under optimized conditions. This work provides a scalable and sustainable strategy to overcome the critical challenges of aqueous Zn-metal batteries, paving the way for their practical application in next-generation energy storage systems.

Nano-Micro Letters2025DOI: 10.1007/s40820-025-01763-8

Buried Interface Regulation with TbCl3 for Highly-Efficient All-Inorganic Perovskite/Silicon Tandem Solar Cells

All-inorganic perovskite materials exhibit exceptional thermal stability and promising candidates for tandem devices, while their application is still in the initial stage. Here, a metal halide doping strategy was implemented to enhance device performance and stability for inverted CsPbI3 perovskite solar cells (PSCs), which are ideal for integration into perovskite/silicon tandem solar cells. The lanthanide compound terbium chloride (TbCl3) was employed to improve buried interface between [4-(3,6-Dimethyl-9H-carbazol-9-yl) butyl] phosphonic acid (Me-4PACz) and perovskite layer, thereby enhancing the crystallinity of CsPbI3 films and passivating non-radiative recombination defects. Thus, the inverted CsPbI3 PSCs achieved an efficiency of 18.68% and demonstrated excellent stability against water and oxygen. Meanwhile, remarkable efficiencies of 29.40% and 25.44% were, respectively, achieved in four-terminal (4T) and two-terminal (2T) perovskite/silicon mechanically tandem devices, which are higher efficiencies among reported all-inorganic perovskite-based tandem solar cells. This study presents a novel approach for fabricating highly efficient and stable inverted all-inorganic PSCs and perovskite/silicon tandem solar cells.

Nano-Micro Letters2025DOI: 10.1007/s40820-025-01750-z

Ultra-Broadband and Ultra-High Electromagnetic Interference Shielding Performance of Aligned and Compact MXene Films

With the rapid development of electronic detective techniques, there is an urgent need for broadband (from microwave to infrared) stealth of aerospace equipment. However, achieving effective broadband stealth primarily relies on the composite of multi-layer coatings of different materials, while realizing broadband stealth with a single material remains a significant challenge. Herein, we reported a highly compact MXene film with aligned nanosheets through a continuous centrifugal spraying strategy. The film exhibits an exceptional electromagnetic interference shielding effectiveness of 45 dB in gigahertz band (8.2–40 GHz) and 59 dB in terahertz band (0.2–1.6 THz) at a thickness of 2.25 μm, owing to the high conductivity (1.03 × 10^6 S m−1). Moreover, exceptionally high specific shielding effectiveness of 1.545 × 10^6 dB cm2 g−1 has been demonstrated by the film, which is the highest value reported for shielding films. Additionally, the film exhibits an ultra-low infrared emissivity of 0.1 in the wide-range infrared band (2.5–16.0 μm), indicating its excellent infrared stealth performance for day-/nighttime outdoor environments. Moreover, the film demonstrates efficient electrothermal performance, including a high saturated temperature (over 120 °C at 1.0 V), a high heating rate (4.4 °C s−1 at 1.0 V), and a stable and uniform heating distribution. Therefore, this work provides a promising strategy for protecting equipment from multispectral electromagnetic interference and inhibiting infrared detection.

Nano-Micro Letters2025DOI: 10.1007/s40820-025-01737-w

Shadow-Assisted Sidewall Emission for Achieving Submicron Linewidth Light Source by Using Normal UV Photolithography

Micro light sources are crucial tools for studying the interactions between light and matter at the micro/nanoscale, encompassing diverse applications across multiple disciplines. Despite numerous studies on reducing the size of micro light sources and enhancing optical resolution, the efficient and simple fabrication of ultra-high-resolution micro light sources remains challenging due to its reliance on precise micro-nano processing technology and advanced processing equipment. In this study, a simple approach for the efficient fabrication of submicron light sources is proposed, namely shadow-assisted sidewall emission (SASE) technology. The SASE utilizes the widely adopted UV photolithography process, employing metal shadow modulation to precisely control the emission of light from polymer sidewalls, thereby obtaining photoluminescent light sources with submicron line widths. The SASE eliminates the need for complex and cumbersome manufacturing procedures. The effects of process parameters, including exposure dose, development time, and metal film thickness, on the linewidth of sources are investigated in detail. It is successfully demonstrated red, green, and blue submicron light sources. Finally, their potential application in the field of optical anti-counterfeiting is also demonstrated. We believe that the SASE proposed in this work provides a novel approach for the preparation and application of micro light sources.

New Carbon Materials (新型炭材料)2025DOI: 10.1016/S1872-5805(NCM2025-3-2)

Controlling interfacial adhesion during the transfer of large-area 2D materials: mechanisms, strategies, and research advances

Large-area two-dimensional (2D) materials, such as graphene, MoS2, WS2, h-BN, black phosphorus, and MXenes, are a class of advanced materials with many possible applications. Different applications need different substrates, and each substrate may need a different way of transferring the 2D material onto it. Problems such as local stress concentrations, an uneven surface tension, inconsistent adhesion, mechanical damage and contamination during the transfer can adversely affect the quality and properties of the transferred material. Therefore, how to improve the integrity, flatness and cleanness of large area 2D materials is a challenge. In order to achieve high-quality transfer, the main concern is to control the interface adhesion between the substrate, the 2D material and the transfer medium. This review focuses on this topic, and finally, in order to promote the industrial use of large area 2D materials, provides a recipe for this transfer process based on the requirements of the application, and points out the current problems and directions for future development.

New Carbon Materials (新型炭材料)2025DOI: 10.1016/S1872-5805(NCM2024-39-02-08)

N, S co-doped coal-based hard carbon prepared by two-step carbonization and a molten salt template method for sodium storage

Hard carbon, known for its abundant resources, stable structure and high safety, has emerged as the most popular anode material for sodium-ion batteries (SIBs). Among various sources, coal-derived hard carbon has attracted extensive attention. In this work, N and S co-doped coal-based carbon material (NSPC1200) was synthesized through a combination of two-step carbonization process and heteroatom doping using long-flame coal as a carbon source, thiourea as a nitrogen and sulfur source, and NaCl as a template. The two-step carbonization process played a crucial role in adjusting the structure of carbon microcrystals and expanding the interlayer spacing. The N and S co-doping regulated the electronic structure of carbon materials, endowing more active sites. Additionally, the introduction of NaCl as a template contributed to the construction of pore structure, which facilitates better contact between electrodes and electrolytes, enabling more efficient transport of Na+ and electrons. Under the synergistic effect, NSPC1200 exhibited exceptional sodium storage capacity, reaching 314.2 mAh g−1 at 20 mA g−1. Furthermore, NSPC1200 demonstrated commendable cycling stability, maintaining a capacity of 224.4 mAh g−1 even after 200 cycles. This work successfully achieves the strategic tuning of the microstructure of coal-based carbon materials, ultimately obtaining hard carbon anode with excellent electrochemical performance.

New Carbon Materials (新型炭材料)2025DOI: 10.1016/S1872-5805(NCM2024-39-03-08)

Controllable construction of CoP nanoparticles anchored on a nitrogen-doped porous carbon as an electrocatalyst for highly efficient oxygen reduction in Zn-air batteries

Exploring cost-efficient and highly-efficient noble metal-free catalysts for the oxygen reduction reactions (ORRs) involved in sustainable energy devices remains a great challenge. Transition-metal phosphides supported on heteroatom-doped carbons have shown potential as alternative candidates for precious metals because of their tunable electronic structures and higher catalytic performance. Phosphating was used to construct CoP nanoparticles (NPs) anchored on a nitrogen-doped porous carbon framework (CoP@NC) from Co NPs loaded on NC, using PH3 gas released from NaH2PO2 during heat treatment. The dodecahedral structure of Co NPs was retained in their transformation to CoP NPs. The CoP@NC electrocatalyst shows a remarkable ORR activity with a half-wave potential up to 0.92 V under alkaline conditions, which is attributed to the combined coupling between the well dispersed CoP nanoparticles on the nitrogen-doped carbon and the efficient mass transport in the porous structure. Zinc-air batteries assembled with the CoP@NC electrocatalyst as a cathode have a high open-circuit voltage of 1.51 V and power density of 210.1 mW cm−2. This work provides a novel strategy to develop low-cost catalysts with an excellent ORR performance to promote their practical use in metal-air batteries.

New Carbon Materials (新型炭材料)2025DOI: 10.1016/S1872-5805(NCM2025-40-01-13)

N/O co-doped microporous carbon as a high-performance electrode for supercapacitors

Carbon materials with adjustable porosity, controllable heteroatom doping and low-cost have been received considerable attention as supercapacitor electrodes. However, using carbon materials with abundant micropores, a high surface area and a high-dopant content for an aqueous supercapacitor with a high energy output still remains a challenge. We report the easy synthesis of interconnected carbon spheres by a polymerization reaction between p-benzaldehyde and 2,6-diaminopyridine. The synthesis involves adjusting the mass ratio of the copolymer and KOH activator to achieve increased charge storage ability and high energy output, which are attributed to the high ion-accessible area provided by the large number of micropores, high N/O contents and rapid ion diffusion channels in the porous structure. At a PMEC∶KOH mass ratio of 1∶1, the high electrolyte ion-adsorption area (2599.76 m2 g−1) and the N/O dopant atoms of the conductive framework of a typical carbon electrode produce a superior specific capacity (303.2 F g−[email protected] A g−1) giving an assembled symmetric capacitor a high energy delivery of 11.3 Wh kg−1@250 W kg−1. This study presents a simple strategy for synthesizing microporous carbon and highlights its potential use in KOH-based supercapacitors.

Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)2025DOI: 10.1088/1674-4926/25010027

Investigating the doping performance of an ionic dopant for organic semiconductors and thermoelectric applications

Doping plays a pivotal role in enhancing the performance of organic semiconductors (OSCs) for advanced optoelectronic and thermoelectric applications. In this study, we systematically investigated the doping performance and applicability of the ionic dopant 4-isopropyl-4′-methyldiphenyliodonium tetrakis(penta-fluorophenyl-borate) (DPI-TPFB) as a p-dopant for OSCs. Using the p-type OSC PBBT-2T as a model system, we demonstrated that DPI-TPFB shows significant doping effect, as confirmed by ESR spectra, ultraviolet−visible−near-infrared (UV−vis−NIR) absorption, and work function analysis, and enhances the electronic conductivity of PBBT-2T films by over four orders of magnitude. Furthermore, DPI-TPFB exhibited broad doping applicability, effectively doping various p-type OSCs and even imparting p-type characteristics to the n-type OSC N2200, transforming its intrinsic n-type behavior into p-type. The application of DPI-TPFB-doped PBBT-2T films in organic thermoelectric devices (OTEs) was also explored, achieving a power factor of approximately 10 μW∙m−1∙K−2. These findings highlight the potential of DPI-TPFB as a versatile and efficient dopant for integration into organic optoelectronic and thermoelectric devices.

Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)2025DOI: 10.1088/1674-4926/25010005

4H-SiC superjunction MOSFET with integrated high-K gate dielectric and split gate

A 4H-SiC superjunction (SJ) MOSFET (SJMOS) with integrated high-K gate dielectric and split gate (HKSG-SJMOS) is proposed in this paper. The key features of HKSG-SJMOS involve the utilization of high-K (HK) dielectric as the gate dielectric, which surrounds the source-connected split gate (SG) and metal gate. The high-K gate dielectric optimizes the electric field distribution within the drift region, creating a low-resistance conductive channel. This enhancement leads to an increase in the breakdown voltage (BV) and a reduction in the specific on resistance (Ron,sp). The introduction of split gate surrounded by high-K dielectric reduces the gate−drain capacitance (Cgd) and gate−drain charge (Qgd), which improves the switching characteristics. The simulation results indicate that compared to conventional 4H-SiC SJMOS, the HKSG-SJMOS exhibits a 110.5% enhancement in figure of merit (FOM, FOM = BV2/Ron,sp), a 93.6% reduction in the high frequency figure of merit (HFFOM) of Ron,sp·Cgd, and reductions in turn-on loss (Eon) and turn-off loss (Eoff) by 38.3% and 31.6%, respectively. Furthermore, the reverse recovery characteristics of HKSG-SJMOS has also discussed, revealing superior performance compared to conventional 4H-SiC SJMOS.

Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)2025DOI: 10.1088/1674-4926/25010022

Research on heterojunction semiconductor photodetectors based on CsPbBr3 QDs/CsPbBrxI3–x QDs

All-inorganic CsPbBr3 perovskite quantum dots (QDs) have attracted extensive attention in photoelectric detection for their excellent photoelectric properties and stability. However, the CsPbBr3 quantum dot film exhibits a high non-radiative recombination rate, and the mismatch in energy levels with the carbon electrode weakens hole extraction efficiency. These reduces the device's performance. To improve this, a semiconductor photodetector based on fluorine-doped tin oxide (FTO)/dense titanium dioxide (c-TiO2)/mesoporous titanium dioxide (m-TiO2)/CsPbBr3 QDs/CsPbBrxI3–x (x = 2, 1.5, 1) QDs/C structure was studied. By adjusting the Br– : I– ratio, the synthesized CsPbBrxI3–x (x = 2, 1.5, 1) QDs showed an adjustable band gap width of 2.284−2.394 eV. And forming a type Ⅱ band structure with CsPbBr3 QDs, which reduced the valence band offset between the active layer and the carbon electrode, this promoted carrier extraction and reduced non-radiative recombination rate. Compared with the original device (the photosensitive layer is CsPbBr3 QDs), the performance of the photodetector based on the CsPbBr3 QDs/CsPbBr2I QDs heterostructure is significantly improved, the responsivity (R) increased by 73%, the specific detectivity rate (D*) increased from 6.98 × 1012 to 3.19 × 1013 Jones, the on/off ratio reached 106. This study provides a new idea for the development of semiconductor tandem detectors.

Transactions of Nonferrous Metals Society of China (中国有色金属学报)2025DOI: 10.1016/S1003-6326(25)67027-0

Enhancing adhesion in columnar crystal Ni coatings via interface-pinning structure optimization

Double glow plasma surface alloying was utilized to synthesize a nickel coating with controlled columnar crystalline architecture. The deposition process was systematically regulated with a fixed source electrode bias of −990 V and precisely controlled deposition temperatures (750, 800, and 850 °C) through cathode bias modulation. Plasma characteristics were quantitatively analyzed through argon emission spectroscopy, enabling precise determination of electron density and temperature. Elemental interdiffusion behavior was comprehensively characterized using electron probe microanalysis, revealing significant interface-pinning effects achieved through strategic manipulation of layer-by-layer and island growth mechanisms. Critical analysis of diffusion coefficients demonstrated comparable magnitudes between the primary diffusion coefficients, along with their cross-diffusion coefficient, suggesting substantial involvement of Inconel718 re-sputtering phenomena in the diffusion dynamics. The coating exhibited exceptional adhesion performance, maintaining structural integrity through 200 rigorous thermal cycling tests without observable delamination.

Ship Mechanics (船舶力学)2025DOI: 10.3969/j.issn.1007-7294.2025.06.008

Monitoring and Data Analysis of Mooring Tension for Floating Platforms

Mooring cable tension is a crucial parameter for evaluating the safety and reliability of a floating platform mooring system. The real-time mooring tension in an actual marine environment has always been essential data that mooring system designers aim to acquire. To address the need for long-term continuous monitoring of mooring tension in deep-sea marine environments, this paper presents a mooring cable tension monitoring method based on the principle of direct mechanical measurement. The developed tension monitoring sensors were installed and applied in the mooring system of the "Yongle" scientific experimental platform. Over the course of one year, a substantial amount of in-situ tension monitoring data was obtained. Under wave heights of up to 1.24 m, the mooring tension on the floating platform reached 16.5 tons. Through frequency domain and time domain analysis, the spectral characteristics of mooring tension, including wave-induced force, slow drift force, and mooring cable elastic restoring force, were determined. The mooring cable elastic restoring force frequency was approximately half of that of the wave signal. Due to the characteristics of the hinge connection structure of the dual module floating platform, under some specific working conditions the wave-induced force was the maximum of the three different frequency forces, and restoring force was the smallest.

Int. Journal of Mining Science and Technology (采矿与安全工程)2025DOI: 10.1016/j.ijmst.2025.06.010

Multi-scale damage and fracture analysis and statistical damage constitutive model of shallow coral reef limestone based on digital core

Coral reef limestone (CRL) constitutes a distinctive marine carbonate formation with complex mechanical properties. This study investigates the multiscale damage and fracture mechanisms of CRL through integrated experimental testing, digital core technology, and theoretical modelling. Two CRL types with contrasting mesostructures were characterized across three scales. Macroscopically, CRL-I and CRL-II exhibited mean compressive strengths of 8.46 and 5.17 MPa, respectively. Mesoscopically, CRL-I featured small-scale highly interconnected pores, whilst CRL-II developed larger stratified pores with diminished connectivity. Microscopically, both CRL matrices demonstrated remarkable similarity in mineral composition and mechanical properties. A novel voxel average-based digital core scaling methodology was developed to facilitate numerical simulation of cross-scale damage processes, revealing network-progressive failure in CRL-I versus directional-brittle failure in CRL-II. Furthermore, a damage statistical constitutive model based on digital core technology and mesoscopic homogenisation theory established quantitative relationships between microelement strength distribution and macroscopic mechanical behavior. These findings illuminate the fundamental mechanisms through which mesoscopic structure governs the macroscopic mechanical properties of CRL.

Int. Journal of Mining Science and Technology (采矿与安全工程)2025DOI: 10.1016/j.ijmst.2025.07.005

A multi-dimensional percussion method for efficient drilling in HDR formations: Rock fragmentation mechanism, drilling energy analysis, and performance optimization

Percussion drilling is a promising approach for hot dry rock (HDR) fragmentation. However, understanding of HDR fragmentation mechanism under multi-dimensional percussion remains limited and hinders the corresponding drilling performance. Herein, an innovative true triaxial multi-dimensional percussion device was developed for the study of HDR fragmentation mechanism under in-situ temperature and stress conditions. Multi-dimensional percussion, involving both axial and torsional components, was applied to drilling in granite and carbonatite rocks sampled from the typical HDR target areas. Multi-scale visualization techniques and a whale optimization-variational mode decomposition algorithm were employed to investigate the rock failure patterns and drilling energy characteristics. Results indicated that multi-dimensional percussion enhances brittle-ductile mixed failure in granite, characterized by transgranular, intergranular, and combined fracture patterns that promote rock cracking. In contrast, carbonatite drillhole displays enhanced brittle fragmentation and tortuous failure surface dominated by transgranular fracture pattern. Frequency-domain characteristics of penetration force signals for multi-dimensional percussion, especially the significant dominant frequency, amplitude, and high-frequency dissipation, indicate an increase in net energy for drilling into HDR and intensified rock fragmentation. Further, the effect of impact frequency on rock fragmentation performance was emphasized to maximize drilling efficiency. The optimal regulation schemes between axial and torsional impact frequencies are identified as 15 Hz + 15 Hz for granite and 30 Hz + 15 Hz for carbonatite. The reliability of the optimization approach was validated through a field test that employed a novel impactor in the geothermal well Fushen-1.

Int. Journal of Mining Science and Technology (采矿与安全工程)2025DOI: 10.1016/j.ijmst.2025.09.012

Dynamic multifractal characteristics and damage evolution of granite pegmatite with varying biotite content based on acoustic emission monitoring

Biotite content critically influences rock mechanical behavior and threatens underground engineering stability. Uniaxial compression tests with acoustic emission (AE) monitoring were conducted on granite pegmatite samples having varying biotite content. Peak frequency distribution analysis, rise angle-average frequency (RA-AF) analysis, multifractal theory, and a dynamic multifractal algorithm were applied to explore the relationship between damage evolution and AE characteristics. Results indicate that increased biotite content reduces uniaxial compressive strength and elastic modulus, enhances plastic deformation, and increases the proportion of shear cracks. The segmented evolution of the dynamic multifractal parameter Dam is biotite-dependent. Oscillations during the elastic phase signify localized shear crack initiation and propagation; their attenuation in the plastic phase reflects frictional closure along biotite cleavage planes, promoting elastic energy storage and delaying release. AE-based damage models and time-varying signals characterize rock damage progression. Stress concentrations around biotite minerals foster localized shear band formation, leading to concentrated shear failure at lower damage levels. Higher biotite content accelerates crack propagation, while smooth cleavage planes lower the fracture energy threshold, reducing strength and stiffness. These findings enhance understanding of biotite-influenced progressive rock damage and underpin stability monitoring and early-warning systems for underground engineering.

Int. Journal of Mining Science and Technology (采矿与安全工程)2025DOI: 10.1016/j.ijmst.2025.11.004

Characterization of the Susceptibility of Ore Particles to Breakdown in High Voltage Pulse Breakage and the Influencing Factors

The susceptibility of ore particles to electrical breakdown plays a critical role for high voltage pulse (HVP) breakage, yet its quantitative characterization still lacks deep understanding. Two indicators, namely breakdown delay time (Td) and breakdown strength (Eb) were compared, based on analysis on the two breakdown modes namely wavefront mode and post-wave mode. It was found that Td is more suitable to characterize the susceptibility of ore particles to electrical breakdown in HVP breakage than Eb. A probabilistic model based on the Weibull distribution is developed to describe the relation of breakdown probability to Td. Regression analyses were conducted to investigate how operating parameters and particle properties influence Td and size reduction degree of ore particles in HVP breakage. The regressed models demonstrate potential capability to predict metallic minerals content and HVP breakage degree based on operating parameters and particle properties.

Journal of Central South University2025DOI: 10.1007/s11771-025-6141-x

Aerodynamic characteristics of a 600 km/h high-temperature superconducting maglev train running in open air considering different suspension gaps

The suspension gap is a critical operational parameter for high-speed maglev trains and significantly impacts their aerodynamic performance. Based on an engineering prototype of the high-temperature superconducting (HTS) pinning maglev train, this study established a detailed three-dimensional model, and then the aerodynamic characteristics of the HTS maglev train at 600 km/h with suspension gaps of 10 mm, 20 mm, and 30 mm were simulated based on the improved delayed detached eddy simulation (IDDES) turbulence model and SST k- ω two-equation. The results demonstrated that the underbody design of the HTS maglev train leads to unique aerodynamic drag and aerothermal distribution phenomena. The head car experiences the smallest drag, while the tail car experiences the largest. The aerothermal temperature on the train's bottom surface progressively increases from the head to the tail. Additionally, the U-shaped track significantly constrains the flow around the train body, forming strong vortex structures. As the suspension gap increases from 10 mm to 30 mm, the airflow velocity in the train-track gap rises, reducing the underbody pressure and decreasing the lift of the head car by 12.43%. The drag of the head car increases by 10.98%, primarily due to changes in pressure drag. Additionally, the temperature at the underbody of the tail car rises further due to significant airflow deceleration. These findings provide valuable insights for advancing the engineering design and application of the high-speed HTS maglev technology.

Chinese Journal of Mechanical Engineering2025DOI: 10.1186/s10033-025-01323-6

Data-Driven Human-in-the-Loop Iterative Learning Fault Estimation Method

For control systems with unknown model parameters, this paper proposes a data-driven iterative learning method for fault estimation. First, input and output data from the system under fault-free conditions are collected. By applying orthogonal triangular decomposition and singular value decomposition, a data-driven realization of the system's kernel representation is derived, based on this representation, a residual generator is constructed. Then, the actuator fault signal is estimated online by analyzing the system's dynamic residual, and an iterative learning algorithm is introduced to continuously optimize the residual-based performance function, thereby enhancing estimation accuracy. The proposed method achieves actuator fault estimation without requiring knowledge of model parameters, eliminating the time-consuming system modeling process, and allowing operators to focus on system optimization and decision-making. Compared with existing fault estimation methods, the proposed method demonstrates superior transient performance, steady-state performance, and real-time capability, reduces the need for manual intervention and lowers operational complexity. Finally, experimental results on a mobile robot verify the effectiveness and advantages of the method.

Chinese Journal of Mechanical Engineering2025DOI: 10.1186/s10033-025-01297-5

A State-of-the-Art Review on the Revolution of Structure and Control of Vehicle Chassis System: from Tradition to Distributed Chassis System

With the advent of in-wheel motors and corner modules, the structure of vehicle chassis subsystems has shifted from traditionally centralized to distributed. This review focuses on the distributed chassis system (DCS) equipped with corner modules. It first provides a comprehensive summary and description of the revolution of the structure and control methods of vehicle chassis systems (including driving, braking, suspension, and steering systems). Given that DCS integrates various chassis subsystems, this review moves beyond individual subsystem analysis and delves into the coordination of these subsystems at the vehicle level. It provides a detailed summary of the methods and architectures used for integrated coordination and control, ensuring that multiple subsystems can function seamlessly as an integrated whole. Finally, this review summarizes the latest distributed control architecture for DCS. It also examines current control theories in the fields of control and information technology for distributed systems, such as multi-agent systems and cyber-physical systems. Based on these two control approaches, a multi-domain cooperative control framework for DCS is proposed.

Chinese Journal of Mechanical Engineering2025DOI: 10.1186/s10033-025-01217-7

Effect of Aluminizing and Laser Shock Peening Treatments on the High-Temperature Oxidation Resistance of AISI 321 Stainless Steel for Solar Thermal Power Heat Exchanger

The high-temperature oxidation resistance of AISI 321 stainless steel used in solar thermal power heat exchangers determines its service life. In this study, aluminizing and subsequent laser shock peening (LSP) treatments were employed to improve the high-temperature oxidation resistance of AISI 321 stainless steel at 620 °C. These two treatments decreased the oxidation rate of AISI 321 steel. Specifically, the optimal oxidation resistance was observed in aluminized steel before oxidation for 144 h owing to the increased entropy of the LSP-treated specimen. After 144 h, LSP-treated steel achieved the best oxidation resistance because of the formation of a protective α-Al2O3 film. Moreover, the large amount of subgrain boundaries formed on the aluminized layer of the LSP-treated samples could act as short-circuit paths for the outward diffusion of Al, facilitating the rapid nucleation of α-Al2O3. Meanwhile, the aluminized layer could isolate the contact between the oxidation environment and matrix, thereby decreasing the oxidation rate. Furthermore, the minimum oxidation parabolic constant was calculated for LSP-treated steel (6.45787 × 10−14), which was 69.18% and 36.36% that of aluminized and 321 steel, respectively, during the entire oxidation process. Therefore, the combination of aluminizing and LSP treatments can improve the high-temperature oxidation resistance of 321 stainless steel, providing a new idea for its surface treatment to achieve a long service life at high temperatures.

Journal of Central South University2025DOI: 10.1007/s11771-025-6144-7

Effect of height of noise barriers on sound source characteristics of aerodynamic noise from high-speed trains

This paper aims to explore the influence of different noise barrier heights on the sound source generation mechanisms of higher-speed trains (400 km/h) using a combination of delayed detached eddy simulation (DDES) and Ffowcs Williams-Hawkings (FW-H) equations. Four cases are investigated and compared, i.e. 1) no barrier, 2) 2.3 m, 3) 3.3 m, and 4) 4.3 m single-side barriers on a bridge. Numerical results show that the presence of noise barriers causes an increase in sound source intensity ranging from 2.1 to 2.8 dB(A). However, the relationship between the barrier height and the increase in sound source intensity varies across different parts of the train. Compared with the head and front-middle cars, the boundary layer is thicker around the rear-middle and tail car areas. A thick boundary layer introduces the influence of the crash wall, causing asymmetry and increases in sound source intensity. This is due to the deceleration region formed between the crash wall and the rail surface, as well as the acceleration region formed by the contraction of the flow channel in the noise barrier, both of which influence the sound source's characteristics. In addition, higher barriers exacerbate asymmetry and increases in sound source intensity.

Journal of Central South University2025DOI: 10.1007/s11771-025-6100-6

Improvement of microstructure and microhardness of AZ31 Mg alloy sheet by cross-forging-bending repeated deformation with sharply increasing temperature

In this study, AZ31 Mg alloy sheets were processed by a severe plastic deformation (SPD) technique called forging-bending repeated deformation (FBRD). The effect on the microstructure and microhardness of AZ31 Mg alloy through FBRD was investigated with increasing temperature treatment and a 90° cross route. The results reveal that the effective strain increases with the number of passes. The flow uniformity is effectively enhanced due to alterations in shear deformation direction. After four passes of deformation, the average grain size is refined by 79.3% compared to the initial specimen. The grain refinement mechanism predominantly originates from the synergistic effects of discontinuous dynamic recrystallization (DDRX), continuous dynamic recrystallization (CDRX), and twinning-induced recrystallization (TDRX). The formation of {1012} extension twins (ET) significantly contributes to coarse grain subdivision and plastic deformation coordinated. Furthermore, pyramidal <c+a> slip activation effectively enhances the plasticity of Mg alloys. By post four-pass processing, the alloy exhibits a microhardness of 81.9HV, primarily governed by fine grain strengthening and dislocation strengthening mechanisms.

Journal of Central South University2025DOI: 10.1007/s11771-025-6114-0

Thermal compression behavior and microstructural evolution of selective laser melted AlMgScZr high-strength aluminum alloys

The AlMgScZr high-strength aluminum alloy fabricated by selective laser melting (SLM) technology exhibits a “bimodal microstructure”, resulting in significant non-uniform deformation during thermal deformation. This study investigates the flow behavior of SLM-processed AlMgScZr aluminum alloy utilizing the Gleeble-1500D thermal simulation machine. The true stress−strain curves were amended based on the friction theory. Through determining the Zener-Hollomon parameters, the correlation between flow stress, deformation temperature, and strain rate during the high-temperature thermoplastic deformation of SLM-processed AlMgScZr aluminum alloy with a “bimodal microstructure” was established. In addition, the microstructural evolution during thermal deformation was analyzed. The results indicated that the predicted flow stress values obtained from the Arrhenius constitutive equation with coupled correction of thermal deformation parameters closely matched the experimental values. The correlation coefficient and the average absolute relative error of the corrected model were 0.999 and 2.766%, respectively, accurately predicting the thermoplastic deformation behavior of SLM-processed high-strength aluminum alloy with a “bimodal microstructure”. Furthermore, hot processing maps at different strains were established, identifying stable and unstable regions under different deformation conditions. Microstructural observations revealed different thermal deformation mechanisms under various deformation temperatures. Specifically, dynamic recrystallization characteristics dominated the microstructure at lower temperatures (300−360 ℃), while dynamic recovery was dominant at higher temperatures (390−500 ℃).

Journal of Central South University2025DOI: 10.1007/s11771-025-6073-5

Ablation enhancing on heterogeneous aluminum/titanium alloy films under femtosecond laser burst irradiation

The femtosecond laser is commonly used for high-quality micromachining of materials. However, the interaction time between the femtosecond laser and the substrate material is extremely short, making it difficult for quantitative measurements and analysis through experiments. In this work, we use a two-temperature model for simulation to study the ablation process of aluminum alloy and aluminum/titanium alloy under femtosecond laser pulse mode. The temperature changes and ablation process of both alloys under femtosecond laser burst irradiation were studied. The study found that when the separation time of sub-pulses was 1 ps, the surface temperature and ablation depth rised with the increase of sub-pulse numbers. A comparison was made between these two alloy types, and enhanced ablation was observed with the heterogeneous aluminum/titanium alloy, up to 34.7% deeper compared to aluminum alloy. Moreover, the detailed theoretical explanation was also discussed. This work provided a basis for efficient ablation of materials with low laser fluence.

Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)2025DOI: 10.1007/s12613-025-3111-0

Densification, microstructure, mechanical properties, and thermal stability of high-strength Ti-modified Al–Si–Mg–Zr aluminum alloy fabricated by laser-powder bed fusion

Micrometer-sized, irregularly shaped Ti particles (0.5wt% and 1.0wt%) were mixed with an Al–Si–Mg–Zr matrix powder, and a novel Ti-modified Al–Si–Mg–Zr aluminum alloy was subsequently fabricated via laser-powder bed fusion (L-PBF). The results demonstrated that the introduction of Ti particles promoted the formation of near-fully equiaxed grains in the alloy owing to the strong grain refinement of the primary (Al,Si)3(Ti,Zr) nanoparticles. Furthermore, the presence of (Al,Si)3(Ti,Zr) nanoparticles inhibited the decomposition of Si-rich cell boundaries and the precipitation of Si nanoparticles in the α-Al cells. The ultimate tensile strength (UTS), yield strength (YS), and elongation of the as-built 0.5wt% Ti (0.5Ti) alloy were (468 ± 11), (350 ± 1) MPa, and (10.0 ± 1.4)%, respectively, which are comparable to those of the L-PBF Al−Si−Mg−Zr matrix alloy and significantly higher than those of traditional L-PBF Al−Si−Mg alloys. After direct aging treatment at 150°C, the precipitation of secondary nanoparticles notably enhanced the strength of the 0.5Ti alloy. Specifically, the 0.5Ti alloy achieved a maximum UTS of (479 ± 11) MPa and YS of (376 ± 10) MPa. At 250°C, the YS of the L-PBF Ti/Al−Si−Mg−Zr alloy was higher than that of the L-PBF Al−Si−Mg−Zr matrix alloy due to the retention of Si-rich cell boundaries, indicating a higher thermal stability. As the aging temperature was increased to 300°C, the dissolution of Si-rich cell boundaries, desolvation of solid-solution elements, and coarsening of nanoprecipitates led to a decrease in the UTS and YS of the alloy to below 300 and 200 MPa, respectively. However, the elongation increased significantly.

Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)2025DOI: 10.1007/s12613-024-3043-0

In-situ research on tensile deformation and microvoid formation in a nuclear pressure vessel steel

Tensile deformation and microvoid formation of quenched and tempered SA508 Gr.3 steel were studied using an in-situ digital image correlation technique and in-situ electron backscatter diffraction (EBSD) measurements. The quenched steel with a mixture of upper bainite and granular bainite exhibited a high ultimate tensile strength (UTS) of ~795 MPa and an elongation of ~25%. After tempering, long-rod carbides and accumulated carbide particles were formed at the interface of bainite–ferrite subunits and prior austenite grain boundaries (PAGBs), respectively. The UTS of the tempered steel decreased to ~607 MPa, whereas the total elongation increased to 33.0% with a local strain of 191.0% at the necked area. In-situ EBSD results showed that strain localization in the bainite–ferrite produced lattice rotation and dislocation pileup, thus leading to stress concentration at the discontinuities (e.g., martensite–austenite islands and carbides). Consequently, the decohesion of PAGBs dotted with martensite–austenite islands was the dominant microvoid initiation mechanism in the quenched steel, whereas microvoids primarily initiated through the fracturing of long-rod carbides and the decohesion of PAGBs with carbides aggregation in the tempered steel. The fracture surfaces for both the quenched and tempered specimens featured dimples, indicating the ductile failure mechanism caused by microvoid coalescence.

Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)2025DOI: 10.1007/s12613-025-3112-z

Hook formation and control mechanisms in continuously cast slabs of ultra-low carbon steel

The hook formation mechanism in continuously cast slabs of ultra-low carbon steel was analyzed in detail through numerical calculations and experimental observations using optical microscopy, and its distribution characteristics were determined. Numerical simulations confirmed that the freezing–overflow mechanism is the primary cause of hook formation. They also revealed that the freezing event occurs unpredictably, while the overflow event takes place during the positive strip time. The average pitch of oscillation marks (OMs) on the slab surface was 8.693 mm, while the theoretical pitch was 8.889 mm, with a difference of approximately 2%. This discrepancy primarily results from varying degrees of overflow, which affects the morphology of the OMs and the positions of their deepest points. Notably, this result further confirmed that the freezing and overflow in the meniscus were indeed caused by the periodic oscillation of the mold. Higher superheat hindered hook formation, leading to a negative correlation between the hook depth distribution around the slab and the temperature distribution within the mold. Therefore, the depth of the corner hook was greater than that of other positions, which was caused by the intensified cooling effect of the corner. Moreover, key factors influencing hook development were analyzed, providing insights into transient fluid flow and heat transfer characteristics within the mold. Transient fluid flow and heat transfer contributed to the randomness and tendency of hook formation. This randomness was reflected in the varying angles of the hooks, whereas the tendency was evident in the negative correlation between superheat and hook length. Based on the randomness and tendency of hook formation and its profile characteristics, a new method for controlling hook depth based on “sine law” is proposed.

Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)2025DOI: 10.1007/s12613-024-2962-0

MOFs-derived flower-like cobalt@carbon multiscale hierarchical composites with effective microwave absorption in the low frequency range

The wave-absorbing materials are kinds of special electromagnetic functional materials and have been widely used in electromagnetic pollution control and military fields. In-situ integrated hierarchical structure construction is thought as a promising route to improve the microwave absorption performance of the materials. In the present work, layer-structured Co-metal-organic frameworks (Co-MOFs) precursors were grown in-situ on the surface of carbon fibers with the hydrothermal method. After annealed at 500°C under Ar atmosphere, a novel multiscale hierarchical composite (Co@C/CF) was obtained with the support of carbon fibers, keeping the flower-like structure. Scanning electron microscope, transmission electron microscope, X-ray diffraction, Raman, and X-ray photoelectron spectroscopy were performed to analyze the microstructure and composition of the hierarchical structure, and the microwave absorption performance of the Co@C/CF composites were investigated. The results showed that the growth of the flower-like structure on the surface of carbon fiber was closely related to the metal-to-ligand ratio. The optimized Co@C/CF flower-like composites achieved the best reflection loss of −55.7 dB in the low frequency band of 6–8 GHz at the thickness of 2.8 mm, with the corresponding effective absorption bandwidth (EAB) of 2.1 GHz. The EAB of 3.24 GHz was achieved in the high frequency range of 12–16 GHz when the thickness was 1.5 mm. The excellent microwave absorption performance was ascribed to the introduction of magnetic components and the construction of the unique structure. The flower-like structure not only balanced the impedance of the fibers themselves, but also extended the propagation path of the microwave and then increased the multiple reflection losses. This work provides a convenient method for the design and development of wave-absorbing composites with in-situ integrated structure.